1. Field of the Invention
This invention relates to electric power switches and to finger barriers for preventing contact with energized components within terminal recesses in the molded casings of such switches.
2. Background Information
In some instances, protection has been provided against finger contact with the terminals of circuit breakers commonly used in residential and light commercial applications, also known as miniature circuit breakers, through configuration of the molded casing. Thus, separate molded parts are needed to provide the circuit breaker with finger protection, requiring the manufacturer to make and stock two models of each breaker to satisfy both those customers that want that feature and those that do not. Also, the users must choose whether or not to purchase a breaker with that feature and cannot later eliminate or add the feature without purchasing a new breaker.
There is room for improvement therefore, in finger protection for electric power switches such as circuit breakers, and in particular, miniature circuit breakers.
The present invention allows a user to selectively apply finger protection to an electric power switch such as a circuit breaker. As another aspect of the invention, the user can install finger protection for easy removal or for permanent installation. At the same time, the manufacturer need only make and stock a single model of the circuit breaker as the finger barrier is a separate item that can be purchased and installed by the user.
More particularly, the invention is directed to a finger barrier for an electric power switch having a molded casing with an open ended terminal recess and transverse mounting slots adjacent each side of the open end of the recess. The finger barrier comprises a planar member having side edges sized to be slideably received in the mounting slots to cover the open end of the external terminal recess. The finger barrier further includes at least one integral locking finger extending along one face of the planar member adjacent one of the side edges. This locking finger is fixed only at a fixed end to the planar member and has a free end that is laterally, resiliently deflectable. A laterally outwardly extending catch on the free end of the locking finger engages a locking ledge associated with the mounting slots. Preferably, the planar member has two of the integral locking fingers, each extending along the one face of the planar member adjacent one of the side edges with each of these locking fingers having a laterally outwardly extending catch which can engage the catch surface in the molded casing. The locking fingers have releases adjacent the free ends which can be actuated to release the latches for removal of the finger barrier from the mounting slots in the molded casing of the switch.
In order to provide the user with the ability to easily remove the barrier or to have the barrier permanently installed, the planar member is insertable in the mounting slots in a first orientation in which the first face, and therefore the locking fingers also, face the terminal recess, and a second orientation in which the other face of the planar member faces the terminal recess. The releases have engagement surfaces which are not accessible when the planar member is inserted in the first orientation so that the planar member cannot be easily removed. However, when the planar member is inserted in the second orientation so that the releases on the locking fingers face outward and are easily accessible, the finger barrier can easily be removed. Preferably, the releases are finger grips which can be squeezed together to disengage the catches from the catch surfaces associated with the mounting slots.
The planar member can have cutouts extending along the side edges, and the locking fingers, except for the fixed ends which are integrally formed with the planar member, register with these cutouts. This provides a finger barrier with no undercuts so that it can be molded in a straight draw mold without the need for slides or other movable mold parts.
The invention also extends to an electric power switch equipped with such a finger barrier.